Apparatus and method for making an electrical component

ABSTRACT

This invention relates to a transformer and more particularly, to a system and method for making a transformer utilizing dynamic magnetic compaction. A coil is placed in a conductive container, and a conductive powder material, such as ferrite, is placed in the container and surrounds the coil and the turns of the coil. A power supply energizes a capacitor which subsequently provides a high energizing current to a second, energizing coil within which the container, material and inner coil are situated, thereby causing the container, powder materials and coil to be compacted to provide an electrical component, such as a transformer, motor, commutator, rotor or choke.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on provisional patent application Ser. No.60/120,244 filed Feb. 16, 1999 and a continuation-in-part of Ser. No.08/681,898 filed Jul. 29, 1996 now U.S. Pat. No. 6,273,963 which is acontinuation-in-part application of Ser. No. 08/368,301 filed Jan. 3,1995, now U.S. Pat. No. 5,611,230, which is a division of Ser. No.07/834,148 filed Feb. 10, 1992, now U.S. Pat. No. 5,405,574.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to electrical components, such as transformers,chokes and, more particularly, to a method and system for formingparticulate or powder-like materials into a unitary, firmly-compactedbody of material to provide transformers, chokes, commutators, rotorsand/or stators for motors.

2. Description of Related Art

Powder metal bodies have been formed by means of pressure and heat. Sucha method has also been used for forming unitary bodies from otherparticulate materials. U.S. Pat. Nos. 5,405,574; 5,611,139; 5,611,230and 5,689,797 all disclose systems and methods for compactingpowder-like materials. For example, U.S. Pat. No. 5,689,797 discloses amethod for producing an annular body wherein a container is filled witha particulate material and an electrically conductive drive member isused to induce a current in the container to cause a compaction pressureto be applied to the particulate material. This causes the material tocompress and compact within the container into an annular body ofmagnetic compacted particulate material.

Similarly, U.S. Pat. No. 5,611,139 discloses a structure for increasingthe density of a powder comprising a support for receiving the powderand an electrically conductive driver positioned adjacent the supportand a connector for connecting the driver to a source of electricalenergy for energizing the driver to create a magnetic field to pressurethe powder, thereby producing an integral part from the powder. Thesepatents are owned by the same Assignee as the present invention, and areincorporated herein by reference and made a part hereof.

FIG. 11 shows a prior art magnetic compaction system having a directcurrent power supply A to which is connected electrical conductors B andC. Connected to the conductor B is a switch D which is also connected toa conductor E. The conductor E and the conductor C have joined therebetween a capacitor. The conductor E is also connected to a switch Gwhich is also connected a connector H. The conductor C and the conductorH are connected to a solenoid I which encompasses an electricallyconductive container I. In operation, the switch is closed, and thecapacitor F is charged from the power supply A. After the capacitor F iscompletely charged, the switch D is opened and the switch G is closed.When the switch G is closed, a large quantity of electrical currentflows from the capacitor F through the solenoid or energizing coil I.When the electrical current flows through the solenoid or energizingcoil I, magnetic pressure is applied upon the electrical conductivecontainer J. This pressure acts inwardly upon the electricallyconductive container J, and the transverse dimensions of theelectrically conductive J are reduced. Thus, compaction occurs withinthe electrically conductive container 38 and the powder-like material Kis compressed and compacted to form a dense body. Thus, the powderousmaterial K within the electrically conductive container J becomes adense body.

Due to the fact that the solenoid or energizing coil I tends to expandradially as current flows there through, suitable means have beenemployed to restrain the coil I against lateral expansion as currentflows there through. For example, as shown in FIG. 11, a wall L mayclosely encompass the energizing solenoid or coil I and restrain thesolenoid or coil I against expansion as current flows there through.

One problem with the current designs and configurations of ferrite-basedtransformers is that they tend to be relatively large. Consequently, thecosts associated with manufacturing and producing such transformerstends to be relatively high, and reliability is not as good as desired.

What is needed, therefore, is a transformer design and manufacturingprocess capable of utilizing dynamic magnetic compaction technologywhich facilitates reducing the size of the parts, such as thetransformers, and which reduces or eliminates the number ofmanufacturing and assembly steps required by prior art techniques.

SUMMARY OF THE INVENTION

This invention provides a system and method wherein powder-like and/orparticulate materials are received in a container along with a insulatedcoil and subject to dynamic magnetic compaction to produce atransformer, choke, rotor or stator for an electric motor and the like.

The method and related structure of this invention applies pressuresgenerated by non-contact electromagnetic forces. These electromagneticpressures are generated by employing suitably shaped energizing coils,such as solenoids or the like, which have the necessary capacity. Anelectrically conductive container is provided wherein a powder-likematerial and an inner coil is situated therein. An electrical current ispassed through a solenoid or energizing coil surrounding the container,and the electrically conductive container is reduced in transverseddimensions, thereby encasing both the particulate material and innercoil to provide a high density body which may be used as a transformeror choke. The compaction of the particulate material is preferablyperformed by electromagnetic compaction as electrical energy is appliedin short time pulses.

An object of this invention is to provide a compacted electricalcomponent having improved manufacturing characteristics, reduced costand improved reliability.

Another object of this invention is to provide an electrical componentmanufactured using dynamic magnetic compaction.

In one aspect, this invention comprises a component part comprising aconductive container for receiving a powderous material, an internalcoil having an insulating coating situated in the conductive container,the conductive container compacting the powderous material about theinternal coil to form the component part when the conductive containeris subject to an electromagnetic field.

In another aspect, this invention comprises a method of making acomponent part comprising the steps of providing a conductive containerfor receiving a powderous material, situating an internal coil having aninsulating coating situated in the conductive container, situating apowderous material in the conductive container, energizing theconductive container to magnetically compact the conductive containerand the powderous material to provide the component part.

In still another aspect, this invention comprises a compaction systemcomprising a power supply, a plurality of conductors coupled to thepower supply, an energizing coil for providing an electromagnetic field,at least one capacitor connected across the energizing coil, at leastone switch coupled to the plurality of conductors and selectivelycoupling the power supply to at least one capacitor and at least oneswitch, the energizing coil be situated relative to a conductivecontainer in order to generate an electromagnetic field to energize aconductive container to magnetically compact a powderous material aboutan internal coil to form a component part, wherein the internal coilcomprises an insulating coating.

Other objects and advantages of the invention will be apparent from thefollowing description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a part prior to compaction in accordancewith one embodiment of the invention;

FIG. 2 is a sectional view of the part shown in FIG. 1;

FIG. 3 is a perspective view of the part shown in FIG. 1 aftercompaction;

FIG. 4 is a sectional view of the part shown in FIG. 3;

FIG. 5 is a perspective view of another part of another embodiment ofthe invention;

FIG. 6 is a perspective view of another part of another embodiment ofthe invention;

FIG. 7 is a schematic view of a magnetic compaction system in accordancewith one embodiment of the invention;

FIG. 8 is a section view of a bobbin in accordance with one embodimentof the invention;

FIG. 9 is a sectional view, taken along the line 9—9 in FIG. 2, of aplurality of wires having an insulative coating which comprise the coil;

FIGS. 10A and 10B are views of wound stators for an electrical motormanufactured in accordance with this invention; and

FIG. 11 is an illustration of a prior art device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-10 illustrate various embodiments of the invention. Asillustrated in FIG. 1, a component, such as a transformer 10, is shownhaving an electrically conductive container 12 for receiving a powderousmaterial 14 and an internal coil 16. The internal coil 16 has aninsulated coating of varnish or other suitable coating.

Although the coil 16 is described as having the insulation mentioned, itshould be appreciated that other types of insulation may be utilized.For example, a suitable pliable varnish or other insulation product,such as FORMVAR, may be utilized as well. Another example of analternate coating could be polyimide. The important point is that thecoil 16 and each of the wires 16 c-16 e (FIG. 9) have an insulation 17to insulate them from the material 14 both during and after compaction.

In the embodiment being described, the powder 14 is preferably either aferrite or iron powder or any other suitable magnetic powder material.The powder 14 is situated in the container 12 and around the coil 16.The container 12, powder 14 and coil 16 are then placed inside anothersolenoid or energizing coil 18 as shown in FIG. 7.

As best illustrated in FIG. 7, the invention comprises a power supply 20coupled to the conductors 22 and 24. Connected to the conductor 22 is aswitch 26 which is also connected to a conductor 28. The conductor 28and the conductor 24 have joined there between a capacitor 30. Theconductor 28 is also connected to a switch 32 which is also connected toa conductor 34. The conductor 24 and the conductor 34 are connected tothe solenoid or energizing coil 18 which encompasses the electricallyconductive container 12. The electrically conductive container 12 isshown as being cylindrical in transverse dimension; however, theelectrically conductive container 12 may be of any suitable or desiredshape and size. The electrically conductive container may be of anysuitable, electrically conductive material, such as, for example,silver, aluminum, copper or other conductive material.

During operation, the switch 26 is closed, and the capacitor 30 ischarged from the power supply 20. After the capacitor 30 is completelycharged, the switch 26 is opened and the switch 32 is closed. When theswitch 32 is closed, a large quantity of electrical current flows fromthe capacitor 30 through the solenoid or coil 36. When the electricalcurrent flows through the coil or solenoid 36, magnetic pressure isapplied upon the electrically conductive container 38. The pressure actssimilarly upon the electrically conductive container 38, and thetransverse dimension of the electrically conductive container 38 arereduced. Thus, compression occurs within the electrically conductivecontainer, and the powder-like material 14 is compacted and compressedaround coil 16. The powderous material 14 becomes a dense body and thecontainer 12, powder 14 and inner coil 16 provide a unitary finishedpart useful in providing a transformer or choke. In order to facilitatethe compacting process, the container 12, powder 14 and soil 16 may beplaced in a retaining die (not shown) having a top and bottom in supportof end 12 a and 12 b of container 12.

As best illustrated in FIGS. 1-5, the coil 16 has a plurality of leads16 a and 16 b which extend outside of end 12 a and end 12 b,respectively, of container 12.

It should be appreciated that the position of the leads may varydepending on the application. For example, FIG. 5 shows leads 1 a and 16b both extending from end 12 a of container 12. In addition, it isenvisioned that the invention may comprise more than one inner coil 16,such as the use of multiple coils 40 and 42 which are stacked as shownin FIG. 6 or they could be interlaced or woven so that the turns of eachcoil are adjacent to each other.

It should appreciated that the performance of the finished part willdepend on the magnetic properties of the consolidated powder 14 and thecompaction between the turns of the coil 16.

The magnetic performance of the powder 14 can be enhanced by usingpowders which have high inherent bonding characteristics andpermeability, such as pure iron powder. Iron powders are preferablebecause of their inherent binding ability during magnetic compaction. Ithas been found that the performance of the component 10 can be enhancedby utilizing plastic coated powders, such as EM-1 products availablefrom Quebec Metal Products, Inc. Performance is also enhanced byimproving the compacted density of the powder 14. In this regard,features of the invention described in U.S. patent application Ser. No.08/681,898, now U.S. Pat. No. 6,273,963 which is assigned to the sameAssignee as the present invention and which is incorporated herein byreference and made apart hereof may be utilized.

Also, it has been found that providing wire 16 in an octagonal orhexagonal or other cross-sectional shaped facilitates improving thecompacted density of part 10 which, in turn, improves performance.

Moreover, it has been found that powder 14 between the turns of coil 16may tend to “short circuit” the magnetic periphery of the component 10.One way to reduce or eliminate this effect is by utilizing anon-magnetic or insulating bobbin 44 (FIG. 8) formed, for example, ofplastic. It has also been found that using a non-magnetic fillermaterial 46 between the wires 16 c-16 e further facilitate preventingany short circuit between or among any of the wires 16 c-16 e.

Another advantage of this compacted powder component design is that itfacilitates dissipating heat because the compacted powder 14 conductsthe heat away from coil 16.

In the embodiment being described, the container 12 (FIGS. 1-5)comprises an exemplary dimension of 16mm diameter, but it should beappreciated that smaller or larger components 10 may be made withoutdeparting from the features of the invention. Further, the wires 16 c-16e which make up coil 16 each have a diameter of about 1mm and are madeof copper, and these dimensions may be varied as desired. After applyingthe techniques of the invention to compact the container 12 and powder14 about coil 16, the dimensions of the finished compacted part 10 areon the order of about 42mm. It should be appreciated, however, that thedimensions and characteristics of the part 10 may be selectively varieddepending upon the application.

It should be appreciated that this invention may be utilized to maketransformers, chokes, commutators, rotors and stators for electricalmotors and any other components which can benefit from the applicationof dynamic magnetic compaction technology described herein. For example,FIG. 10 shows a cross-sectional view of a wound stator 50 having thewires 16 compacted therein to provide a finished stator which, when usedwith a rotor (not shown) and power supply (not shown) provide anelectric motor capable of performing work.

While the methods herein described, and the forms of apparatus forcarrying these methods into effect, constitute preferred embodiments ofthis invention, it is to be understood that the invention is not limitedto these precise methods and forms of apparatus, and that changes may bemade in either without departing from the scope of the inventiondisclosed herein.

What is claimed is:
 1. A component part comprising: a powderousmaterial; a continuous body having an insulating coating situated in aconductive container; said powderous material being compacted about saidcontinuous body to form said component part in response to saidconductive container being subject to an electromagnetic field.
 2. Thecomponent part as recited in claim 1 wherein said component part is atransformer, motor, commutator, rotor or choke.
 3. The component part asrecited in claim 1 wherein said continuous body is an internal coilcomprising a plurality of coils.
 4. The component part as recited inclaim 3 wherein each of said plurality of coils define a non-circularshape in cross-section.
 5. The component part as recited in claim 4wherein said non-circular shape is hexagonal or octagonal.
 6. Thecomponent part as recited in claim 1 wherein said continuous bodycomprises an internal coil comprising a plurality of leads extendingoutside said container.
 7. The component part as recited in claim 6wherein said conductive container comprises a first end and a secondend, said plurality of leads extending out of only one of said first endor second end.
 8. The component part as recited in claim 6 wherein saidconductive container comprises a first end and a second end, saidplurality of leads extending out of at least said first and second ends.9. The component part as recited in claim 1 wherein said insulativecoating comprises one of following: varnish, FORMVAR or polyimide. 10.The component part as recited in claim 3 wherein said plurality of coilscomprises adjacent coils, said component part comprising a non-magneticfiller situated between said adjacent coils.
 11. The component part asrecited in claim 1 wherein said powderous material comprises a ferriteor iron powder.
 12. The component part as recited in claim 1 whereinsaid electrically conductive container comprises aluminum, silver,copper or steel.
 13. The component part as recited in claim 1 whereinsaid continuous body comprises a conductive coil wrapped around anon-conductive bobbin and said bobbin and conductive coil are situatedin said electrically conductive container.
 14. The component part asrecited in claim 1 wherein said continuous body comprises an internalcoil of copper.
 15. The component part as recited in claim 1 whereinsaid continuous body comprises an internal coil comprising a diameter ofless than 1 mm.
 16. A method of making a component part comprising thesteps of: providing a conductive container for receiving a powderousmaterial; situating a continuous body having an insulating coatingsituated in the conductive container; situating a powderous material insaid conductive container; energizing said conductive container tomagnetically compact said conductive container and said powderousmaterial to provide said component part.
 17. The method as recited inclaim 16 wherein said component part is a transformer, motor,commutator, rotor or choke.
 18. The method as recited in claim 16wherein said method further comprises the step of: providing acontinuous body in the form of an internal coil comprising a pluralityof coils.
 19. The method as recited in claim 16 wherein said methodfurther comprises the step of: providing a continuous body in the formof a plurality of coils each defining a non-circular shape incross-section.
 20. The method as recited in claim 19 wherein saidnon-circular shape is hexagonal or octagonal.
 21. The method as recitedin claim 16 wherein said continuous body comprises an internal coilcomprises a plurality of leads, said situating step further comprisesthe step of: situating said internal coil into said conductive containersuch that said plurality of leads extend outside said container.
 22. Themethod as recited in claim 16 wherein said container comprises a firstend and a second end, said situating step further comprising the step ofsituating said continuous body into said conductive container such thatsaid plurality of leads extend out of only one of said first end orsecond end.
 23. The method as recited in claim 16 wherein said containercomprises a first end and a second end, said situating step furthercomprising the step of situating said continuous body into saidconductive container such that said plurality of leads extend out of atleast said first and second ends.
 24. The method as recited in claim 16wherein said method comprises the step of: providing said continuousbody comprising an internal coil comprising an insulative coatingcomprising one of following: varnish, FORMVAR or polyimide.
 25. Themethod as recited in claim 18 wherein said method further comprises thestep of: providing a plurality of coils comprising adjacent coils;situating a non-magnetic filler between said adjacent coils.
 26. Themethod as recited in claim 16 wherein said situating step comprises thestep of; situating a ferrite or iron powder into said conductivecontainer before said energizing step.
 27. The method as recited inclaim 16 wherein said providing step further comprises the step of:providing an electrically conductive container of aluminum, silver,copper or steel.
 28. The method as recited in claim 16 wherein saidmethod further comprises the step of: wrapping said internal coil arounda non-conductive bobbin and said bobbin and conductive coil are situatedin said electrically conductive container.
 29. The method as recited inclaim 16 wherein said providing step comprises the step of: providing anconductive container of copper.
 30. The method as recited in claim 16wherein said continuous body comprises a diameter of less than 1 mm. 31.A compaction system comprising: a power supply; a plurality ofconductors coupled to said power supply; an energizing coil forproviding an electromagnetic field; at least one capacitor connectedacross said energizing coil; at least one switch coupled to saidplurality of conductors and selectively coupling said power supply tosaid at least one capacitor and said at least one switch; saidenergizing coil be situated relative to a conductive container in orderto generate an electromagnetic field to energize a conductive containerto magnetically compact a powderous material about an internal coil toform a component part, wherein said internal coil comprises aninsulating coating.
 32. The compaction system as recited in claim 31wherein said component part is a transformer, motor, commutator, rotoror choke.
 33. The compaction system as recited in claim 31 wherein saidinternal coil comprises a plurality of coils.
 34. The compaction systemas recited in claim 3 wherein each of said plurality of coils define anon-circular shape in cross-section.
 35. The compaction system asrecited in claim 31 wherein said non-circular shape is hexagonal oroctagonal.
 36. The compaction system as recited in claim 31 wherein saidinternal coil comprises a plurality of leads extending outside saidcontainer.
 37. The compaction system as recited in claim 36 wherein saidcontainer comprises a first end and a second end, said plurality ofleads extending out of only one of said first end or second end.
 38. Thecompaction system as recited in claim 36 wherein said containercomprises a first end and a second end, said plurality of leadsextending out of at least said first and second ends.
 39. The compactionsystem as recited in claim 32 wherein said insulative coating comprisesone of following: varnish, FORMVAR or polyimide.
 40. The compactionsystem as recited in claim 33 wherein said plurality of coils comprisesa djacent coils, said component part comprising a non-magnetic fillersituated between said adjacent coils.
 41. The compaction system asrecited in claim 31 wherein said powderous material comprises a ferriteor iron powder.
 42. The compaction system as recited in claim 31 whereinsaid electrically conductive container comprises aluminum, silver,copper or steel.
 43. The compaction system as recited in claim 31wherein said conductive coil is wrapped around a non-conductive bobbinand said bobbin and conductive coil are situated in said electricallyconductive container.
 44. The compaction system as recited in claim 31wherein said internal coil is copper.
 45. The compaction system asrecited in claim 31 wherein said internal coil comprises a diameter ofless than 1 mm.